OBJECTIVES: The chronic demyelinative myelopathy induced in mice by intracerebral inoculation of tissue culture cell-adapted DNA virus will be studied under the electron microscope; myelin from DA virus-infected mouse spinal cord will be studied by x-ray diffraction methods; longitudinal studies of cell-mediated and humoral immunity to DA virus and to central nervous system (CNS) antigens will be carried out in DA virus myelopathy; 4) Further electron microscopic immunological and biochemical studies of DA virus will be carried out; 5) Cell-mediated immunity in patients with amyotrophic lateral sclerosis will be studied by means of lymphocyte transformation to viral, CNS, acetylcholine receptor and muscle antigens. BIBLIOGRAPHIC REFERENCES: Hochberg, F.H., Fiorino, P., Lehrich, J.R., Astrom, K.E. and Richardson, E.P.: Mononucleosis-associated subacute sclerosing panencephalitis. Acta Neuropath 34:33, 1975. Powell, H.P., Lehrich, J.R. and Arnason, B.G.W.: Electron microscopic appearance of the DA virus, a demyelinating murine virus. J. Neuropath. Exper. Neurol. 35(3), 1976.